PURPOSE:

To explore the influence of gingival biotype and width of keratinized gingiva on peri-implant bone tissue, soft tissue health, and esthetic outcome of the papilla surrounding single posterior maxillary implants.

METHODS:

Seventy-eight patients who underwent single posterior maxillary implant surgery from May 2019 to September 2022 were selected, involving the placement of 78 implants. Based on periodontal probing outcomes one month post-restoration, the patients were divided into thin gingival biotype group(n=32) and thick gingival biotype group(n=46). Comparisons were made six months after implant restoration regarding buccal keratinized mucosa width(KMW), peri-implant bone tissue [implant bone loss(IBL)], soft tissue health [modified plaque index (mPLI), modified bleeding index for implants (mBLI), probing pocket depth (PPD)], and esthetic effect of the papilla [papilla index score (PIS), food impaction, gingival margin color satisfaction index (GMCS)]. Statistical analysis was performed with SPSS 27.0 software package.

RESULTS:

The thick gingival biotype group showed significantly greater keratinized gingival width compared to the thin gingival biotype group (P＜0.05). Spearman correlation analysis revealed a positive correlation between gingival biotype and keratinized gingival width(r=-0.416, P=0.000). For peri-implant bone tissue, bone loss in the thin gingival biotype group was significantly higher than that in the thick gingival biotype group. In soft tissue health, the probing pocket depth for implants in the thin gingival biotype group was significantly less than that in the thick gingival biotype group. In terms of esthetic effect of the papilla, PES score in the thin gingival biotype group was significantly lower than in the thick gingival biotype group(P＜0.05). Pearson correlation analysis showed a negative correlation between gingival biotype and papilla index score, GMCS, bleeding on probing, and PPD, but a positive correlation with food impaction, bone loss and mPLI(P＜0.05). The width of keratinized gingiva was positively correlated with papilla index score, GMCS, bleeding on probing and PPD, but negatively correlated with food impaction, bone loss and mPLI(P＜0.05). There was significantly difference between thin and thick gingival biotype groups for KMW >2 mm(P＜0.05). A significant difference was showed in thick gingival biotype group when KMW ≤2 mm and ＞2 mm(P＜0.05).

CONCLUSIONS:

Gingival biotype and keratinized mucosa width significantly influence peri-implant bone and soft tissue health as well as esthetic outcome of the papilla around single posterior maxillary implants, offering guidance for predicting the long-term success and esthetic outcomes of implants.